Abstract: A method for maintaining a data storage system is disclosed. The method may include monitoring for receipt of a first broadcast message from a first data storage node, where the first broadcast message may indicate that the first data storage node is operating correctly. The method may also include detecting that the first data storage node is malfunctioning based on not receiving the first broadcast message for a predetermined period of time. The method may also include initiating a data replication procedure based on detecting that the first data storage node is malfunctioning. The data replication procedure may include sending a first multicast message to a plurality of data storage nodes requesting identification of a second data storage node that maintains a copy of a file stored on the first data storage node.

Abstract: A method for data storage implemented in a data storage system is disclosed. Data storage nodes may be interconnected by means of a communications network. The method may include sending a request for a first data item to a plurality of storage nodes. The first data item may include a reference to a second data item stored in the storage system. The method may include receiving the first data item from at least one storage node, and sending a request for the second data item to the plurality of storage nodes based on the reference included in the first data item.

Abstract: A method for maintaining a data storage system is disclosed. The method may include monitoring a first data storage node. The method may also include detecting a condition regarding the first data storage node, and the condition may indicate that at least one file stored on the first data storage node is to be replicated. The method may also include updating a replication list based on detecting the condition, and the replication list may include an identification of the at least one file and priority information for replication of the at least one file. The method may include performing a data replication procedure based on the replication list, where the data replication procedure may include sending a first multicast message to a plurality of other data storage nodes requesting identification of a second data storage node that maintains a copy of the at least one file.

Abstract: There is disclosed a method for writing data in a data storage system comprising a plurality of data storage nodes, the method being employed in a server running an application which accesses data in the data storage system, and comprising: sending a multicast storage query to a plurality of said storage nodes; receiving a plurality of responses from a subset of said storage nodes, said responses including a storage node property; selecting at least two storage nodes in the subset for storing said data, based on said responses, wherein the selecting is based on a data property of the data to be stored and a storage node property.

Abstract: There is provided a method implemented in a data storage system including a plurality of storage nodes connected to each other via a communications network. At least one storage node of the plurality of storage nodes may store a first data item. The data item may be arranged to include a reference to a second data item stored in the data storage system. The method may include providing an identifier of the second data item. The method may also include providing status information about the first data item. The identifier may be used to update the first data item, for example based on the status information. The first data item may be stored at the at least one storage node.

Abstract: The present invention relates to a distributed data storage system comprising a plurality of storage nodes. Using unicast and multicast transmission, a server application may write data in the storage system. When writing data, at least two storage nodes are selected based in part on a randomized function, which ensures that data is sufficiently spread to provide efficient and reliable replication of data in case a storage node malfunctions.

Abstract: The present invention relates to a distributed data storage system comprising a plurality of storage nodes. Using unicast and multicast transmission, a server application may write data in the storage system. When writing data, at least two storage nodes are selected based in part on a randomized function, which ensures that data is sufficiently spread to provide efficient and reliable replication of data in case a storage node malfunctions.

Abstract: A method and device for maintaining data in a data storage system, comprising a plurality of data storage nodes, the method being employed in a storage node in the data storage system and comprising: monitoring and detecting, conditions in the data storage system that imply the need for replication of data between the nodes in the data storage system; initiating replication processes in case such a condition is detected, wherein the replication processes include sending multicast and unicast requests to other storage nodes, said requests including priority flags, receiving multicast and unicast requests from other storage nodes, wherein the received requests include priority flags, ordering the received requests in different queues depending on their priority flags, and dealing with requests in higher priority queues with higher frequency than requests in lower priority queues.

Abstract: There is provided a method and server for retrieving data from a data storage system including a plurality of storage nodes. The method may include sending a multicast message to at least a subset of the storage nodes. The multicast message may include a request for the subset of storage nodes to send the data. The multicast message may further include a data identifier, indicating the data to be retrieved. Moreover, the method may include receiving data from a first storage node of the subset of storage nodes. The data received from the first storage node may correspond to the requested data. At least the act of sending a multicast message or the act of receiving data from the first storage node may be performed on a condition that an estimated size of the data is less than a predetermined value.

Abstract: There is provided a method and server for retrieving data from a data storage system including a plurality of storage nodes. The method may include sending a multicast message to at least a subset of the storage nodes. The multicast message may include a request for the subset of storage nodes to send the data. The multicast message may further include a data identifier, indicating the data to be retrieved. Moreover, the method may include receiving data from a first storage node of the subset of storage nodes. The data received from the first storage node may correspond to the requested data. At least the act of sending a multicast message or the act of receiving data from the first storage node may be performed on a condition that an estimated size of the data is less than a predetermined value.

Abstract: The present invention relates to a distributed data storage system comprising a plurality of storage nodes. Using unicast and multicast transmission, a server application may read and write data in the storage system. Each storage node may monitor reading and writing operations on the system as well as the status of other storage nodes. In this way, the storage nodes may detect a need for replication of files on the system, and may carry out a replication process that serves to maintain a storage of a sufficient number of copies of files with correct versions at geographically diverse locations.

Abstract: A method and device for maintaining data in a data storage system, comprising a plurality of data storage nodes, the method being employed in a storage node in the data storage system and comprising: monitoring and detecting, conditions in the data storage system that imply the need for replication of data between the nodes in the data storage system; initiating replication processes in case such a condition is detected, wherein the replication processes include sending multicast and unicast requests to other storage nodes, said requests including priority flags, receiving multicast and unicast requests from other storage nodes, wherein the received requests include priority flags, ordering the received requests in different queues depending on their priority flags, and dealing with requests in higher priority queues with higher frequency than requests in lower priority queues.

Abstract: A method for data storage implemented in a data storage system is disclosed. Data storage nodes may be interconnected by means of a communications network. The method may include sending a request for a first data item to a plurality of storage nodes. The first data item may include a reference to a second data item stored in the storage system. The method may include receiving the first data item from at least one storage node, and sending a request for the second data item to the plurality of storage nodes based on the reference included in the first data item.

Abstract: The present invention relates to a distributed data storage system comprising a plurality of storage nodes. Using unicast and multicast transmission, a server application may read and write data in the storage system. Each storage node may monitor reading and writing operations on the system as well as the status of other storage nodes. In this way, the storage nodes may detect a need for replication of files on the system, and may carry out a replication process that serves to maintain a storage of a sufficient number of copies of files with correct versions at geographically diverse locations.

Abstract: A method and device for maintaining data in a data storage system, comprising a plurality of data storage nodes, the method being employed in a storage node in the data storage system and comprising: monitoring and detecting, conditions in the data storage system that imply the need for replication of data between the nodes in the data storage system; initiating replication processes in case such a condition is detected, wherein the replication processes include sending multicast and unicast requests to other storage nodes, said requests including priority flags, receiving multicast and unicast requests from other storage nodes, wherein the received requests include priority flags, ordering the received requests in different queues depending on their priority flags, and dealing with requests in higher priority queues with higher frequency than requests in lower priority queues.

Abstract: A method for data storage implemented in a data storage system is disclosed. Data storage nodes may be interconnected by means of a communications network. The method may include sending a request for a first data item to a plurality of storage nodes. The first data item may include a reference to a second data item stored in the storage system. The method may include receiving the first data item from at least one storage node, and sending a request for the second data item to the plurality of storage nodes based on the reference included in the first data item.

Abstract: There is provided a method and server for retrieving data from a data storage system including a plurality of storage nodes. The method may include sending a multicast message to at least a subset of the storage nodes. The multicast message may include a request for the subset of storage nodes to send the data. The multicast message may further include a data identifier, indicating the data to be retrieved. Moreover, the method may include receiving data from a first storage node of the subset of storage nodes. The data received from the first storage node may correspond to the requested data. At least the act of sending a multicast message or the act of receiving data from the first storage node may be performed on a condition that an estimated size of the data is less than a predetermined value.

Abstract: A method for data storage implemented in a data storage system is disclosed. Data storage nodes may be interconnected by means of a communications network. The method may include sending a request for a first data item to a plurality of storage nodes. The first data item may include a reference to a second data item stored in the storage system. The method may include receiving the first data item from at least one storage node, and sending a request for the second data item to the plurality of storage nodes based on the reference included in the first data item.

Abstract: There is disclosed a method for writing data in a data storage system comprising a plurality of data storage nodes, the method being employed in a server running an application which accesses data in the data storage system, and comprising: sending a multicast storage query to a plurality of said storage nodes; receiving a plurality of responses from a subset of said storage nodes, said responses including a storage node property; selecting at least two storage nodes in the subset for storing said data, based on said responses, wherein the selecting is based on a data property of the data to be stored and a storage node property.

Abstract: There is provided a method implemented in a data storage system including a plurality of storage nodes connected to each other via a communications network. At least one storage node of the plurality of storage nodes may store a first data item. The data item may be arranged to include a reference to a second data item stored in the data storage system. The method may include providing an identifier of the second data item. The method may also include providing status information about the first data item. The identifier may be used to update the first data item, for example based on the status information. The first data item may be stored at the at least one storage node.